For a variety of reasons, including legal requirements in the United States, system operators of systems which provide content to subscribers, such as cable and television system operations, are required to include the capability of delivering emergency alert messages over one or more channels, e.g., television channels, in response to one or more emergency alert messages (EAS). EAS alert capabilities are often required to include, in addition to the ability to provide an audio and/or video alert when required, support for EAS zones, e.g., corresponding to different geographic regions.
Various approaches have been taken to support EAS requirements. For example, some system operations have included support for EAS banner overlay where a banner including an EAS message may be overlayed over a portion of video content which is being delivered. Banner insertion into a content stream which is being delivered can be processor intensive and may involve decoding and re-encoding video content being delivered so that the banner is incorporated as part of the individual video frames being delivered and/or so that the end devices overlay a banner with the EAS message over the video content being delivered.
The addition of servers used to insert EAS banners by merging frame content in a stream which is being delivered with EAS banner content can be expensive given the complexity of the video content merging process on a per frame basis, e.g., in the real time period corresponding to an EAS message.
The use of servers to perform banner merging with video frames is not only costly, but it does not scale well in the context of multiple zones where different content streams may be delivered to different zones requiring a large number of servers to enable the real time merging of EAS banners with individual frames on a per zone basis.
Other approaches to EAS messaging which have been used with some success include what is sometime referred to as “force tuning” set top boxes to EAS channels. This approach normally involves sending signals to set top boxes which control the set top box causing it to tune to a channel, e.g., frequency band, used to broadcast an EAS message. At the end of the EAS message, the individual set top boxes are sent another instruction, e.g., from a network headend, to tune back to the channel they were previously tuned to.
As should be appreciated, the “force tune” approach has the disadvantage of requiring tuning commands to be provided to set top boxes, the tuning to the EAS message channel and then the retuning back to the channel previously being viewed. Not only does this require a fair number of commands to be sent and processed, but it also involves delays in that the messaging to the set top boxes and the retuning all involve some amount of time. In the case of emergency alert messages relating to tornados and/or other critical events, delays of even a few seconds may make a difference in the usefulness of the emergency alert message.
In view of the above discussion, it should be appreciated that there is a need for improved methods and/or apparatus for providing emergency alert messages. In particular, it would be desirable if methods and/or apparatus could be developed which would allow emergency alert messages to be supplied to set top boxes without having to force tune set top boxes to an EAS message channel and/or without having to merge an alert message with the content of individual video frames.